Chair backrest



FIG. 1 is an isometric view of a chair backrest in accordance with thenew design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a right side elevational view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a rear elevational view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is an isometric view of an alternative embodiment of the chairbackrest configured as a barstool.

The broken lines in the figures are for illustrative purposes only andform no part of the claimed design.

The ornamental design for a chair backrest, as shown and described.